民用燃料燃烧碳质组分及VOCs排放特征

选取北京市地区典型生物质燃料（玉米芯、玉米秆、黄豆秆、草梗、松木、栗树枝、桃树枝）以及民用煤（烟煤、蜂窝煤）在实验室内进行了模拟燃烧实验，对燃烧产生的颗粒物及气体样品进行采集，采用Model 2001A热/光碳分析仪对不同粒径段颗粒物中的有机碳、元素碳进行测定，采用AgilentGC-MS 5977/7890B气质联用仪对燃烧烟气中的挥发性有机物进行分析.研究表明：除蜂窝煤OC、EC的排放因子在2.5~10μm粒径范围内达到最大，其他8种固体燃料燃烧产生的OC、EC的排放因子最大值均在0~2.5μm粒径范围内.薪柴（栗树枝、桃树枝、松木）、秸秆（玉米芯、玉米秆、黄豆秆、草梗）和民用煤（蜂窝煤、烟煤）3类物质燃烧排放VOCs的物种分类差异较大.薪柴和民用煤燃烧排放的卤代烃以及含氧有机物的质量分数明显高于秸秆的质量分数；在同一类别中VOCs物质分布趋势一致.3种薪柴平均总VOCs的排放系数为2.02g/kg，4种秸秆平均总VOCs的排放系数为6.89g/kg，2种民用煤平均总VOCs的排放系数为2.03g/kg，秸秆类的排放因子最大.玉米芯、玉米秆、黄豆秆和草梗的臭氧生成潜势较高，而栗树枝、桃树枝、松木、烟煤以及蜂窝煤的臭氧生成潜势较低，且分布类似.烯烃类、烷烃类、芳香烃类是固体燃料燃烧臭氧生成潜势贡献较大的VOCs物质.

Carbon compositions and VOCs emission characteristics of civil combustion fuels

The typical biomass fuels in Beijing (made of corn cob, corn stalks, soybean stalks, straw stalks, pine, chestnut branches, peach branches) and civil coal (bituminous coal, honeycomb coal) were selected and combustion experiments were simulated in the laboratory. After collecting particulate matters and gas samples from combustion, organic carbon (OC) and elemental carbon (EC) in different particle size fractions of particulate matter were measured by Model 2001A Thermal/Photocarbon Analyzer, and the VOCs in combustion flue gas were analyzed with Agilent GC-MS 5977/7890B GC-MS as well. The results showed that for honeycomb coal, the emission factor of OC and EC reached the maximum with the particle size of 2.5~10μm, for all the other 8solid fuels, the emission factor of OC and EC were maximum with the particle size of 0~2.5μm. The composition of VOCs from the combustion of these three types of fuels, firewood (chestnut branches, peach branches and pine), straw (corn cob, corn stalks, soybean stalks, straw stalks) and civil coal (honeycomb and bituminous coal), are quite different. The mass fractions of halogenated hydrocarbons and oxygenated organic matter emitted from firewood and civil coal combustion are significantly higher than that from straw type fuels. Within each fuel, VOCs composition is relatively similar. The average total VOCs emission factor was 2.02g/kg for the firewood type, 6.89g/kg for the straws, and 2.03g/kg for the civil coals. VOCs from corn cob, corn stalk, soybean and straw stem have higher ozone formation potential than that from chestnut, peach, pine, bituminous and honeycomb, nonetheless, the composition was similar among the latter group. The VOCs, such as Alkenes, alkanes and aromatic hydrocarbons from solid fuel combustion, were big contributors to the ozone formation potential.